I've seen him fight when he was an amateur. He's big and he's strong, but he's clumsy. I know I can beat him.

8 seconds sound clip from the Rocky IV (1985) movie soundboard.

You can hear this line at 00:12:31 in the Blu-ray version of the movie.

Quote context

[...]

- Shall we have a demonstration?

- Please do.

- Thank you.

- A normal heavyweight averages 700 pounds of pressure per square inch.

- As you can see, Drago averages 1,850 pounds, so the result's quite obvious.

- And what results are those?

- Whatever he hits, he destroys.

- I've seen him fight when he was an amateur. He's big and he's strong, but he's clumsy. I know I can beat him.

- Why do you want to fight again?

- Let's just say it's something I believe in.

- You can do your homework.

- Okay. Later, Dad. Later, Uncle Paulie. Later, Apollo.

[...]